In plasma enhanced substrate processing systems, such as physical vapor deposition (PVD) chambers, process kits may be utilized to prevent undesired deposition on one or more chamber components. In some embodiments, a process kit may include a shield, such as a two piece shield, where a first shield surrounds a volume between a sputtering target and a substrate support and a second shield surrounds a source material of the target. The inventors have discovered that adjacent surfaces between the first and second shields can be a site for the undesired deposition of source material from the target. For example, the source material can flake off the adjacent surfaces and contaminate the substrate on which source material is being deposited. Further, the inventor's have discovered that misalignment between any of the aforementioned shield components and the target can result in arcing between RF hot and grounded surfaces and/or non-uniformities in sputtering and deposition of the source materials.
Accordingly, the inventors have provided improved process kit shields for use in plasma enhanced processing systems.